Discrete semiconductor device and method of forming sealed trench junction termination

Abstract

A discrete semiconductor device has a substrate with a first conductivity type of semiconductor material. A first semiconductor layer is formed over the substrate. The first semiconductor layer having the first conductivity type of semiconductor material. A second semiconductor layer over the first semiconductor layer. The second semiconductor layer has a second conductivity type of semiconductor material. A trench is formed through the second semiconductor layer and extends into the second semiconductor layer. The trench has a rounded or polygonal shape and vertical sidewalls. The trench is lined with an insulating layer and filled with an insulating material. A boundary between the first and second semiconductor layers forms a p-n junction. The trench surrounds the p-n junction to terminate the electric field of a voltage imposed on the second semiconductor layer. The discrete semiconductor device can also be a transistor, thyristor, triac, or transient voltage suppressor.

What is claimed: 
     
       1. A semiconductor device, comprising:
 a substrate including,
 (a) a first semiconductor layer, 
 (b) a second semiconductor layer disposed over the first semiconductor layer, and 
 (c) a semiconductor component formed in the second semiconductor layer; 
 
 a first trench extending through the second semiconductor layer and only partially through the first semiconductor layer around the semiconductor component; 
 a first insulating material deposited in the first trench as a first isolation trench around the semiconductor component; 
 a second trench disposed around the semiconductor component and extending only partially through the second semiconductor layer; and 
 a second insulating material deposited in the second trench as a second isolation trench around the semiconductor component. 
 
     
     
       2. The semiconductor device of  claim 1 , wherein the first trench extends completely around the semiconductor component. 
     
     
       3. The semiconductor device of  claim 1 , further including an insulating layer formed over a sidewall of the first trench. 
     
     
       4. The semiconductor device of  claim 3 , wherein the sidewall of the first trench is substantially vertical. 
     
     
       5. The semiconductor device of  claim 1 , wherein the semiconductor component includes a diode, transistor, rectifier, transient voltage suppressor, thyristor, or triac. 
     
     
       6. The semiconductor device of  claim 1 , wherein the first trench has a rounded or polygonal shape. 
     
     
       7. The semiconductor device of  claim 1 , wherein the first insulating material is planar with a surface of the second semiconductor layer. 
     
     
       8. A semiconductor device, comprising:
 a substrate; 
 a first semiconductor layer formed over a first surface of the substrate; 
 a first semiconductor component formed over the first surface of the substrate; 
 a first trench extending through the first semiconductor layer and partially through the substrate; 
 a second semiconductor layer formed over a second surface of the substrate opposite the first surface of the substrate; 
 a second semiconductor component formed over the second surface of the substrate; 
 a second trench extending through the second semiconductor layer and partially through the substrate; and 
 an insulating material deposited in the first trench and second trench. 
 
     
     
       9. The semiconductor device of  claim 8 , further including an insulating layer formed over a sidewall of the first trench and further formed over a sidewall of the second trench. 
     
     
       10. The semiconductor device of  claim 9 , wherein the sidewall of the first trench is substantially vertical and the sidewall of the second trench is substantially vertical. 
     
     
       11. The semiconductor device of  claim 8 , wherein the first trench extends completely around the first semiconductor component and the second trench extends completely around the second semiconductor component. 
     
     
       12. The semiconductor device of  claim 8 , wherein the first semiconductor component or second semiconductor component includes a diode, transistor, rectifier, transient voltage suppressor, thyristor, or triac. 
     
     
       13. The semiconductor device of  claim 8 , wherein the first trench and second trench have a rounded or polygonal shape. 
     
     
       14. The semiconductor device of  claim 8 , wherein the insulating material is planar with a surface of the first semiconductor layer.